EXCERPT: “I was surprised, because these women were really pushing for Hillary until they found out about the Monsanto connection, and then they dropped her like a hot potato,” said James Berge, Democratic Party chairman for Worth County, Iowa. “It’s quite a big issue,” he said. “There’s people who are just wild about all the use of GMOs.”—

Hillary Rodham Clinton’s ties to agribusiness giant Monsanto, and her advocacy for the industry’s genetically modified crops, have environmentalists in Iowa calling her “Bride of Frankenfood” — putting yet another wrinkle in her presidential campaign’s courtship of liberal activists who are crucial to winning the state’s Democratic caucuses.

The backlash against Mrs. Clinton for her support of genetically modified organisms (GMO), which dominate the corn and soybean crops at the heart of Iowa’s economy, manifested itself at a recent meeting of the Tri-County Democrats, where members gauged support for the former secretary of state.

A large faction of women voiced strong support for Mrs. Clinton’s candidacy until the GMO issue came up, prompting them to switch allegiances to Sen. Bernard Sanders of Vermont, a liberal stalwart challenging her for the Democratic nomination.

“I was surprised, because these women were really pushing for Hillary until they found out about the Monsanto connection, and then they dropped her like a hot potato,” said James Berge, Democratic Party chairman for Worth County, Iowa.

“It’s quite a big issue,” he said. “There’s people who are just wild about all the use of GMOs.”

The issue gives liberal voters another reason to be skeptical of Mrs. Clinton, whom they already distrust because of her cozy relationship with Wall Street and the centrist philosophy that she and her husband, former President Bill Clinton, long embraced.

Mrs. Clinton likely will keep the GMO debate on a back burner when she makes her second swing through Iowa this week. She has scheduled stops Monday and Tuesday to rally grass-roots support and discuss ideas to expand small businesses in the state.

She enjoys a massive advantage in the polls in Iowa, leading Mr. Sanders 60 percent to 15 percent in a recent Quinnipiac University survey. While not an overt threat to her, Mr. Sanders has inched up in the polls since he entered the race April 30, and his liberal agenda is popular with the party activists.

“Iowa is a big agricultural state, but we’ve got to realize some of the food that we are producing in this country is going to cause great health effects down the road, and then it’s probably going to be too late to try to fix it,” said Mr. Berge. “You can’t even wash this pesticide off, because it is in the plants themselves, and you are digesting it, and it goes into your body. It’s not a good thing.”

GMOs include seeds engineered in a laboratory to have certain traits, such as resistance to such herbicides as Monsanto’s widely used Roundup. Most of the corn and soybeans in the U.S. are genetically modified. Much of it goes into animal feed, but it also is in popular processed food ingredients like high fructose corn syrup and soybean oil.

Iowa leads the country in the production of corn and ranks among the top producers of soybeans.

Agribusiness interests claim that GMO crops are more resistant to pests, drought and cold weather, increasing yields and limiting the use of pesticides.

But environmentalists argue that genetically modified food is unhealthy and promotes excessive use of pesticides.

A new scientific study bolstered environmentalists’ concerns by finding the herbicide Roundup could be linked to a range of health problems and diseases, including Parkinson’s, infertility, and cancers. The study published last month in the scientific journal Entropy also reported evidence that residue of glyphosate, a chief ingredient in the weed killer, has been found in food.

In the GMO debate, Mrs. Clinton has consistently sided with the chemical companies

Her top campaign operative in Iowa is former Monsanto lobbyist Jerry Crawford, who’s also a veteran of Iowa politics and Clinton campaigns.

Her history of backing GMOs dates back to her early days in Arkansas as a lawyer with the Rose Law Firm, which represented Monsanto and other agribusiness leaders.

Just last year, Mrs. Clinton gave a paid speech at a biotech industry conference in San Diego, where she championed GMOs and advised the executives and investors to give their products an image makeover.

Big ag also has been a big donor to the Clinton Foundation, the family charity at the center of pay-to-play accusations involving foreign donors while Mrs. Clinton ran the State Department.

Monsanto gave the foundation between $501,250 and $1 million. Dow Chemical Company, which is among the top GMO players, gave between $1 million and $5 million, according to financial disclosures by the Clinton Foundation.

Mrs. Clinton’s support for Monsanto and genetically modified food was one of the factors that contributed to her embarrassing third-place finish in the 2008 Iowa caucuses, said Laura Hubka, vice chair of the Tri-County Democrats, a club in Howard, Mitchell and Worth counties along the state’s norther border with Minnesota.

“We are very environmentally active,” said Ms. Hubka. “It would be great to hear her come out and speak against Monsanto and what it has done to our farmers as far as our corn production now. There’s a lot of things Monsanto has done that [have] made us unhappy.”

Ms. Hubka said that Mrs. Clinton could make amends by getting out in front of the GMO issue.

“It seems like she is out in front of several issues [like] the immigration issue, [and] she’s been out in front of working on police issues that have come up recently,” said Ms. Hubka. “We are hoping to see her make a turn also against Monsanto. That would be fantastic for us.”

Mark Shelley, chairman of the political science department at Iowa State University, said that Mrs. Clinton likely would be able to weather opposition from environmentalists at the caucuses because farming is a pocketbook issue for most Iowans.

“So much of Iowa’s economy is connected to agriculture directly, and to closely related industries such as farm implement manufacturing, seed companies and food processing, that agribusiness interests are often seen as having outsize influence on the state’s political climate,” he said.

“It is important to note, though, that Democratic caucuses tend to attract people with more active interests in issues, which in that party translates to caucus attenders who are generally more progressive-leaning than the party as a whole,” Mr. Shelley said.